Prenatal and early postnatal motor development and its importance in recognizing developmental disorders

The normal central nervous system is characterized by both activity and reactivity. Under normal circumstances the former leads the latter. In abnormal conditions reactivity may predominate, usually in the form of reflexes and abnormal postural reactions. Ultrasound registration shows that the first spontaneous motor movements can be seen in the seventh to eighth gestational week. Movement patterns develop fast, and in mid-pregnancy all patterns are observed that can be found in the term newborn baby. During the second half of pregnancy movement patterns are refined: the first differentiation leading to variable and fluent movements. The intrauterine movements are qualitatively more or less similar to those seen in normal preterm babies, the main difference being that the latter as to counteract gravity forces to a greater extent. Qualitative changes of the movement patterns signal deteriorating intrauterine conditions. Stereotyped quality of movement can be a sign of abnormal development. During infancy normal development is characterized by great variability in performance, developmental sequences and relationships. Stereotype performance and strong relationship between the various motor functions, reactions and reflexes should arouse the suspicion that there may be a disturbance in development.